Arbor holder



June 27, 1944. T. M. STEPHEN 23,52,415

ARBOR HOLDER.

Filed Nov. 2, 1942 no r as: 11E: r\

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Patented June 27, 1944 UNITED STATES PATENT. OFFICES-.

ARBOR notmin. Thomas M. Stephens, Montgomery, W. Va. Application November 2, 1942, seri l No. 464,309

4 Claims. (or vii-89.2)

1 This invention relates to devices for dressing rockdrills and ha as its principal object the provision of an arbor holder which will be simple in construction, economical in manufacture and highly efficient in use.

Another object of my invention is to provide in bitffo'rming and shaping devices, a guide structurefor holding a mandrel in axial alignment with forming ,dies.

I A further objector thisinvention is to prof'Ot her objects will appear hereinafter.

ff'fIhe invention consists in the novel combination and arrangement of parts to be hereinafter described and claimed; The invention willbe best understood by reference to the accompanying drawing showing "the; preferred form of construction, and in 1 isa-perspeotiveview of a used rock drill bit about to be mounted upon an-arbor;

Fig. 2 is aperspective vi'ewof my new arbor holder illustrating the arbor with bit attached about to be placed the holder; "Fig. 3 is a longitudinal vertical section through the-same 'and taken alongline-3-3 in Fig. 2

the arbor in place;

Fi .4 is an end elevational view of the arbor holder as seen from line 4-4 in Fig." 2; and

Fig. 5 is a perspective view'of a finished rock drill bit after the dressing operation. l This invention has to do with machines for shaping and sharpening drop forged cutter bits such as the-one illustrated in the drawing here- Numerous types and kinds of cutter bits have been devised each differing in form as to Ill having a plurality ,of

0 the cutting face to provide cutter bits for various with a standard inside thread adapted for shaping process. Such is the nature of the machine with which the present invention is concerned. A used and distorted bit is shown in Fig. 1 about to be screwed onto the studendllE of a mandrel or arbor l6 whereby the bit may be handled during the redressing operation. ;The

bit It) is first placed in a forge and brought to a suitable forging heat. By means of tongs, (not shown) the bit 10 is held while the stud l5 is screwed into the threadv I4 on the shank l3. The arbor l6 now forms a tool holder for the bit which is placed under a vertical drop forge (not shown) to straighten the prongs ll and dispose them substantially parallel to the long axisof the bit [0. The arbor I6 with' bit I O'attach'ed is now ready to be placed in the arbor holder :for

the redressing process. v I The arbor holder is generally indicated atill and has apedestal l8 which is adapted to be 'afiixe'd to a foundation by means of lag screws 'chine, generally indicated at 30 and later to be mentioned, and is provided with a guide block 23 atone end which block 23 is suitably bolted to the-bed plate 22. The block 23 has a yoke formation 24 into which may be placed the arbor "IG for holding the latter in the plane ofthe hammering machine. There is a screw block 25 boltedadjacent the opposite end of the bed plate 22 which screw block 25 has an elongated threaded opening 26 aligned with-the=yoke formation 24. A threaded arbor 21. having a 'hand wheel 28 atone end is screwed into the opening 25- and presents an abutment face 29 which 'is adapted to be adjusted .and set'against the butt end 3| of the arbor lfi'toi-take up? the shock produced by the horizontal drop, forging machine 3!). 1 l

The forging machine 30 may be any one of a number of well known types which include a horizontally reciprocable hammer (not shown) for reciprocation over a bed plate 32 and carrying a forming head 33. In conjunction with my arbor holder there is provided a forming die or anvil 34. This anvil 34 is preferably mount-- ed on the end of the bed plate 32 of the horizontal forging machine 30. This anvil '34 is placed as; aforesaid in alignment with the reciprocable hammer head 33 and an axial plane struck through the yoke 24 and the threaded arbor 27.

. The anvil 34 is formed to provide an abut ment shoulder 35 which is adapted to abut a collar 36 formed on the arbor l6 adjacent the stud l5 and against which collar 36 the shank I3 is screwed (Fig. 3). The anvil 34 is also provided with a semi-annular groove 31 into which the collar 36 is placed while the shank of the arbor I6 is rested in a trough 38 formed in the abutment shoulder 35.

It will be remembered that the bit I0 when screwed onto the arbor I6 is heated to a forging temperature so that the fibre thereof may readily be shaped by the force of a drop forge hammer. The bit I0 having already been conditioned as aforesaid with the prongs II substantially parallel to the long axis of the bit, the bit and arbor l6 are now placed in the anvil 34 and yoke 24 respectively, the threaded arbor being screwed up with the abutment face 29 in abutting relation with respect to the butt end 3| of the arbor 16 as shown in Fig. 3.

The anvil has a die formation 39 at its edge closest adjacent the hammer head 33 and it will be understood that this die formation 39 may be varied in form to correspond in shape to the particular type of bit being dressed.

With the arbor I6 and bit It! thus placed in the arbor holder [1, the horizontal dropforge machine 36 is operated to cause the hammer and head 33 to reciprocate several times with the head 33 inflicting several blows against the face l2 of the bit, thus causing the prongs l I to resume a shape defined by a crevice II formed in the die formation 39 of the anvil. The arbor I6 is lifted by hand from the yoke and anvil to rotate other prongs ll into position with respect to the crevices II, and the hammer head 33 again reciprocated against the face l2 of the bit until finally the cutting bit is redressed to present again a uniformly shaped and'sharpened cutting face. The bit is then unscrewed and allowed to cool and thereafter is ready for use as a rock drill, the final product being illustrated in Fig. 5,

It will be noted that by reason of the arrangement of the anvil 34 and its grooves 31. and trough 38, together with the yoke 24 in block 23 and the abutment provided by the threaded arbor 21, the mandrel or arbor l6 may be casually placed in position by hand and will assuredly be-snugly held in alignment with the line of force from the drop forging machine 30. Also, the abutment shoulder 35 will hold the red hot bit it] .in position to receive the blows from the hammer head 33 and will take the shock of such blows as will the threaded arbor ,21, thus assuring a firm foundation for the whole instrument being worked upon and relieving shearing action at the point where the collar 36 joins the shank of the arbor I6.

While I have illustrated and described the preferred form of construction for carrying my invention into effect, this is capable of variation and -modification without departing from the spirit of the invention. I, therefore, do not wish to be limited to the precise details of construction set forth, but desire to avail myself of such variations and modificationsas come within the scope of the appended claims.

Having thus described my invention, what I claim as new and desire to protect by Letters Patent is:

1'. A device for holding a drill head on an anvil in alignment with a trip hammer of a drop forge comprising an arbor for holding said drill head, a collar on said arbor, a groove formed in said anvil and forming a seat for said collar, an adjacent wall of said groove providing a vertical abutment for said collar and adapted to maintain said arbor and drill head in position when blows are inflicted as aforesaid, and means cooperating with said groove and abutment to support said arbor in axial alignment with the line of force of said hammer, said last named means comprising a pedestal, a bed plate supported by said pedestal, a yoke block on said bed plate and disposed in axial alignment with said hammer and said anvil to receive said arbor and align the latter with the hammer and anvil. 2. A device for holding a drill head on an anvil in alignment with a trip hammer of a drop forge comprising an arbor for holding said drill head, a collar on said arbor, a groove formed in said anvil and forming a seat for said collar, an adjacent wall of said groove providing a vertical abutment for said collar and adapted to maintain said arbor and drill head in position when blows are inflicted as aforesaid, and means dooperating with said groove and abutment to support said arbor in axial alignment with the line of force of said hammer, said last named means comprising a yoke block disposed in axial alignment with said hammer and said anvil to receive said arbor and align the latter with the hammer and anvil, and an abutment fors'aid arbor and arranged on the side of said yoke op,- posite to said anvil and adapted to absorb shock conveyed along said arbor from the hammer;

3. A device for holding a drill head o'n an anvil in alignment with a trip hammer of adrop forge comprising an arbor for holding said drill head, a collar on said arbor, a groove formed in said anvil and forming a seat for said collar; an adjacent wall of said groove providing avertical abutment for said collar and adapted to maintain said arbor'and drill head in positionwhen blows are inflicted as aforesaid, and means coloperating with saidgroove and abutment to support said arbor in axial alignmentwith the line of force of said hammer, said last named means comprising a pedestal, a bed plate supported by said pedestal, a yoke :block on said bed platefand disposed in axial alignment with said hammer and said anvil to'receive said arbor and align the latter with the hammer and anvil, and an abutment for, said arbor and arranged ongxthe side of said yoke opposite to said anvil and adapt;- ed to absorb shock conveyed along saidarbor from the hammer. 4. A device for a rock drill dressing machin which machine includes a reciprocable hammer head for inflicting blows against a rock drillwblt and an arbor for holding said rock drill bit, comprising an anvil disposed to receive blows from. said hammer head and providing. ayoke formation and a shoulder adjacent thereto,v a collar formation on the arbor adapted to -lie against said shoulder to hold the rock drill zbit between said anvil and the hammer head, and a guide block spaced from said anvil on theiside thereof opposite the hammer head and; adapted to receive the arbor to hold the latter in align.- ment with said anvil and hammer head, andwan abutment for the. arbor and arranged; on'the side of said guide block' opposite said anvil-in alignment with thelatter and :the hammerhead to absorb the shock conveyed through the rock drill bit and said arborfrom the hammeryheact THOMAS'M; STEPHENS): 

